The present invention generally relates to dynamic control, from network side, of network selection by terminals connecting to the network, via subscriber group based cell broadcast.
In network deployments like Long Term Evolution (LTE) or LTE-Advanced networks, in order to enable efficient offloading of traffic from the main radio link to e.g. Wi-Fi networks (Wi-Fi offloading), operators prefer having some degree of control over the terminal's (e.g. user equipment (UE)) Wi-Fi usage. Current major smart phone platforms (iOS, Android and Windows Phone) work such that, when a detected Wi-Fi network is known by the device (that is, a user or a provisioning server has configured certain Wi-Fi network details so that the UE can connect to that Wi-Fi network), the UE automatically connects to that Wi-Fi (assuming that the Wi-Fi radio module of the UE is not turned off by the user).
In such scenario, which Wi-Fi network is used by the UE can be only influenced by the operator (the network) by affecting which Wi-Fi networks are known by the UE. That is, if the operator wants the UE to use a certain Wi-Fi network, the certain Wi-Fi network is made known to the UE, and if a certain Wi-Fi network should not be used anymore by the UE, that certain Wi-Fi network is to be removed from known Wi-Fi networks within a UE's internal Wi-Fi database.
Besides proprietary solutions to handle the above mentioned requirements of the operator/network, which are deployed only in very small scale, the Third Generation Partnership Project (3GPP) Access Network Discovery and Selection Function (ANDSF) provides standardized functionality which may handle the scenario described above. Namely, ANDSF server and UE client functionality is defined. ANDSF relies on an Open Mobile Alliance (OMA) device management (DM) framework for ANDSF information exchange between the server (i.e. the ANDSF Server) and client (i.e. the UE).
According to 3GPP specifications, ANDSF provides inter-system mobility policy (ISMP), Discovery Information as well as inter-system routing policy (ISRP), which are described below.
ISMP can be used to prioritize Wi-Fi networks over each other and also over 3GPP networks. ISMP is used when the UE does not support simultaneous 3GPP and Wi-Fi radio usage. An example of prioritized ISMP would be Wi-Fi with service set identifier (SSID)=Operator_A having highest priority followed by any Wi-Fi available, with 3GPP radio accesses having the lowest priority. Following this policy, the UE would connect to the network access of available network accesses having the highest priority according to the policy. ISMP was introduced in 3GPP Release 8.
Discovery Information can be used to tell the UEs where certain Wi-Fi networks are available. Each Wi-Fi network may be associated with a location area identifier that can be based e.g. on 3GPP identifiers (location area code (LAC), tracking area code (TAC) and/or cell identities (ID), etc.) to allow the device to optimize Wi-Fi scanning. Also, it is possible to configure Wi-Fi access details, like used extensible authentication protocol (EAP) methods and their respective credentials or pre-shared key (PSK) for certain Wi-Fi network. In practice, Discovery Information can be used to make Wi-Fi networks “known” to the UEs. That is, a UE is able connect to the identified Wi-Fi networks after receiving respective Discovery Information.
ISRP can be used to prioritize radio accesses for specific applications. Applications are identified with internet protocol (IP) 5-tuples, e.g. with IP addresses, IP protocol and IP protocol port numbers. With Rel-11, it is also possible to identify traffic with fully qualified domain network (FQDN) or with operating system (OS)-specific Application ID. With ISRP, it is assumed that the device (i.e. UE) can use both 3GPP and Wi-Fi radio accesses simultaneously. An example of prioritized ISRP would be for YouTube traffic (identified application) Wi-Fi with SSID=Operator_A having highest priority followed by any Wi-Fi available, with 3GPP radio accesses having the lowest priority. Following this policy, the UE would use for the identified application the network access of available network accesses having the highest priority according to the policy.
This information (ISMP, Discovery Information, ISRP) is conveyed in an ANDSF Management Object (MO). Additionally, ANDSF MO can be used to convey location information of the UE to the ANDSF server during ANDSF session.
It is to be noted that ANDSF server and client implementations may support any combination of the above described ANDSF functionality.
It is further to be noted that ANDSF is not very suitable for real-time operations due to its dependency on the OMA DM framework.
In particular, setting up an ANDSF session can take several seconds. Further the transfer between the server and client of the actual ANDSF information may cause a further delay. Thus, the basic use model for ANDSF is such that the ANDSF information (ISMP, Discovery Information, ISRP) is provisioned to the UE, and then UE uses the same set of information for a certain period of time. Such period may for example be one week. Consequently, the actual ANDSF information can be considered as being static, which does not support a dynamic control.
In order to provide a dynamic ANDSF that could react e.g. to changing load conditions as requested by the network operators, cell broadcast technology might be used to deliver ANDSF content to the UEs. This cell broadcast technology may include 2G/3G Cell Broadcast Service (CBS) and also 4G Earthquake and Tsunami Warning System (ETWS) and Commercial Mobile Alert Service (CMAS) systems.
Presently, the cell broadcast technology for both full ANDSF content delivery and partial content delivery is just used locally to modify ANDSF content provided by (optional) standard ANDSF server.
However, in view of the above, the problem arises that cell broadcast technology does not consider different subscriber groups since the same data is sent to every terminal in the area (broadcast). For example in an overload situation, an operator might want to keep some subscriber segment in 3GPP network, while another subscriber segment might be intended to be put into wireless local area networks (WLAN) when available.
Hence, there is a need to provide for subscriber group based cell broadcast.